Operation Characteristics And Safety Analysis Of Variable Frequency Electromechanical Systems

With the continuous advancement of energy saving and emission reduction work in China,the application of frequency conversion speed regulation in large-capacity water pump and fan type load has been increasing,and remarkable economic effects have been achieved.However,after the frequency conversion transformation of the equipment,many safety problems such as shaft cracks and blade damage have occurred.These security problems not only bring huge economic losses to users,but also hinder the promotion and application of energy-saving and consumption reduction of frequency conversion.Therefore,this paper analyzes the causes of the safety of the shafting caused by the variable frequency speed regulation,and analyzes the factors that affect the safety of the shafting system under different control modes.Firstly,the basic principle and topology of each part of the large-capacity frequency conversion electromechanical system are studied,and the corresponding mathematical model is established.Then,according to the constant voltage frequency ratio control operation mode of the high voltage inverter,the causes of the shafting damage are analyzed from the angle of the harmonic component of the voltage and the natural frequency coupling of the transmission shaft system.The analysis of the motor in the cascade type multilevel frequency conversion the harmonic component of the electromagnetic torque driven by the device.A complete simulation model was built in the Simulink simulation platform,and the theoretical analysis results were verified.In addition,the basic idea and implementation method of vector control technology are analyzed for the vector control operation mode of high-voltage inverter.Aiming at the coupling relationship between the control system and the shafting system,the simulation model of the machine-electric-control coupling in the Simulink simulation platform is used to simulate and analyze the influence of the control parameters on the torsional vibration of the vector system.Finally,according to the actual frequency conversion reconstruction scheme,the life damage of the shafting system under different working conditions is analyzed and calculated,and the safety operation optimization suggestions for the equipment frequency conversion speed regulation are given.